Method and system for removing hydrocarbon deposits from heat exchanger tube bundles

Abstract

A method and system for removing hydrocarbon deposits from a heat exchanger tube bundle using an organic solvent. After contact with a heat exchanger tube bundle, the contaminated organic solvent may be treated to remove solids, base waters, and/or suspended hydrocarbons, and then again contacted with a heat exchanger tube bundle for the removal of hydrocarbon deposits. This allows for the removal of hydrocarbon deposits from a heat exchanger tube bundle in an efficient and environmentally friendly manner. The treatment of the heat exchanger tube bundle is also preferably performed using a method and system by which, through contact of the heat exchanger tube bundle with an organic solvent, a large percentage of hydrocarbon deposits are removed from the heat exchanger tube bundle in a short period of time.

What is claimed: 
     
       1. A heat exchanger tube bundle cleaning system comprising:
 a cleaning chamber comprising a base defining a reservoir containing an organic solvent and a hinged lid; 
 a cradle configured to support a heat exchanger tube bundle in the reservoir, the cradle comprising one or more rollers configured to rotate the heat exchanger tube bundle; 
 a shell-side spraying system configured to spray a pressurized stream of organic solvent against a shell-side surface of the heat exchanger tube bundle; 
 a heating element configured to raise or lower the temperature of the organic solvent; 
 wherein the floor of the cleaning chamber is sloped downward from the side walls of the base to a recess in the center of the reservoir and wherein an auger runs along the recess. 
 
     
     
       2. The heat exchanger tube bundle cleaning system of  claim 1 , further comprising a tube-sheet spraying system configured to spray a pressurized stream of organic solvent into the individual tubes of the heat exchanger tube bundle while the heat exchanger tube bundle is within the reservoir. 
     
     
       3. The heat exchanger tube bundle cleaning system of  claim 2 , wherein the tube-sheet spraying system comprises one or more nozzles configured to travel across the tube sheet of the heat exchanger tube bundle. 
     
     
       4. The heat exchanger tube bundle cleaning system of  claim 1 , wherein the underside of the lid comprises a rinsing manifold configured for spraying liquid along the length of the heat exchanger tube bundle. 
     
     
       5. The heat exchanger tube bundle cleaning system of  claim 1 , wherein the cradle comprises one or more telescoping members that provide the cradle with an adjustable length, an adjustable width, or a combination thereof. 
     
     
       6. The heat exchanger tube bundle cleaning system of  claim 5 , wherein the one or more telescoping members are configured so that the location of the rollers within the reservoir is adjustable. 
     
     
       7. The heat exchanger tube bundle cleaning system of  claim 1 , wherein the shell-side spraying system comprises an isolation valve configured to limit the spraying of organic solvent to a desired length within the reservoir. 
     
     
       8. The heat exchanger tube bundle cleaning system of  claim 1 , further comprising a lifting system operably connected to the cradle and configured to raise the cradle out of the reservoir and lower the cradle into the reservoir. 
     
     
       9. The heat exchanger tube bundle cleaning system of  claim 8 , wherein the lifting system comprises at least a first one or more hydraulic cylinders and a second one or more hydraulic cylinders,
 wherein the first one or more hydraulic cylinders and the second one or more hydraulic cylinders are configured to operate independently so that the cradle may be brought to an inclined position to allow for draining of the organic solvent from the heat exchanger tube bundle back into the reservoir for reuse and/or recycle. 
 
     
     
       10. The heat exchanger tube bundle cleaning system of  claim 1 , further comprising a series of gas inlets configured to carry a gas evenly across the surface of the reservoir. 
     
     
       11. The heat exchanger tube bundle cleaning system of  claim 10 , further comprising a series of gas outlets configured to extract vapors across the surface of the reservoir, the series of gas outlets being located on an opposite side of the reservoir from the series of gas inlets. 
     
     
       12. The heat exchanger tube bundle cleaning system of  claim 1 , further comprising an organic solvent recovery unit comprising
 i. a separation unit configured to separate solids, base waters, or both from contaminated organic solvent; and 
 ii. a distillation unit having a tops outlet from which a purified organic solvent fraction is withdrawn and a bottoms outlet from which hydrocarbon contaminants are withdrawn. 
 
     
     
       13. The heat exchanger tube bundle cleaning system of  claim 12 , wherein the system is configured so that organic solvent can be circulated between the cleaning chamber and the organic solvent recovery unit. 
     
     
       14. The heat exchanger tube bundle cleaning system of  claim 12 , wherein the separation unit comprises a plurality of knock-out plates. 
     
     
       15. The heat exchanger tube bundle cleaning system of  claim 1 , wherein the cradle comprises a plurality of rollers; and
 wherein the rollers are driven with independent hydraulic motors. 
 
     
     
       16. A heat exchanger tube bundle cleaning system comprising:
 a cleaning chamber comprising a base defining a reservoir containing an organic solvent and a hinged lid; 
 a cradle configured to support a heat exchanger tube bundle in the reservoir, the cradle comprising one or more rollers configured to rotate the heat exchanger tube bundle; 
 a shell-side spraying system configured to spray a pressurized stream of organic solvent against a shell-side surface of the heat exchanger tube bundle; 
 a heating element configured to raise or lower the temperature of the organic solvent; 
 a lifting system operably connected to the cradle and configured to raise the cradle out of the reservoir and lower the cradle into the reservoir, wherein the lifting system comprises at least a first one or more hydraulic cylinders and a second one or more hydraulic cylinders, the first one or more hydraulic cylinders and the second one or more hydraulic cylinders being configured to operate independently so that the cradle may be brought to an inclined position to allow for draining of the organic solvent from the heat exchanger tube bundle back into the reservoir for reuse and/or recycle. 
 
     
     
       17. The heat exchanger tube bundle cleaning system of  claim 16 , further comprising a tube-sheet spraying system configured to spray a pressurized stream of organic solvent into the individual tubes of the heat exchanger tube bundle while the heat exchanger tube bundle is within the reservoir. 
     
     
       18. The heat exchanger tube bundle cleaning system of  claim 16 , wherein the underside of the lid comprises a rinsing manifold configured for spraying liquid along the length of the heat exchanger tube bundle.